Electrostatic or static charges can be generated both on the inside and outside of structural components such as pipes, vessels, etc. One source of static charge generation and accumulation results from the flow of fluids with conductivities of less than 10,000 pS/m inside non-conducting structural components. Static discharges can occur inside equipment such as insulating pipes, so counter-measures are necessary when operating a pipe that is only partially filled and may contain a flammable vapor. Static charge accumulation can also give rise to external discharges, potentially igniting a flammable atmosphere in the region surrounding the equipment.
Petroleum products typically contain or have associated with them corrosive materials such as carbon dioxide, hydrogen sulfide, and chlorides, etc. In composite pipe systems, there is a continuous resin rich reinforced corrosion liner that isolates process fluids from the structural wall, preventing lead prone penetration through the structure. Because composite materials provide improved corrosion resistance and reduced maintenance requirements, they have been employed as replacement of expensive steels and alloys in the containment of petroleum products. In pipelines conveying petroleum products, static charges accumulate at the fluid-pipe wall interface.
There is a need for an improved method to dissipate static charges generated in structural components for use in containing/conveying petroleum products, particularly piping systems comprising composite materials for improved corrosion resistant properties. There is also the need for an improved method to join composite pipes while maintaining conductivity for use in the oil & gas industry.